CZERO adds area for testing detector technology and for a possible future experiment

by Mike Perricone

It all started with an idea by then-Director John Peoples in the spring of 1996.

Looking ahead to the Lab shutdown for construction of the Main Injector, Peoples instigated a month-long workshop inviting anyone interested in a new colliding beam experimental area to discuss what kind of physics they wanted to do, and what facilities would be needed.

Out of that workshop came a sketchy prototype proposal, along with the scheduling of another meeting at the Lab: the December 1996 Workshop on Heavy Quark Physics at CZero, which sounds straightforward enough, except that there was still no place to do any kind of physics at CZero at the time. That December workshop was held to gauge the level of interest in moving ahead to build what was called a modest experimental hall at the Tevatron's CZero straight section.

"There was a lot of enthusiasm," Peter Garbincius recalled, "and John and DOE said, `Go ahead and build it.'"

Less than three years later, the $5 million project has been completed to the stage of having an experimental hall below ground and an assembly building above ground. Garbincius, who helped organize the initial workshop, recently received a Fermilab Employee Recognition Award for his work as project manager on the CZero Area Experimental Hall construction.

The CZero enclosure will be used for testing new detector technologies; for fixed target experiments; and for "modest-sized" collider experiments. A modest-sized example would be studying heavy (charm and bottom) quarks, using existing equipment recycled from several 800 GeV fixed target experiments whose runs have ended. The new area will give the Lab a third interaction point for collider experiments, along with CDF and DZero.

"One of the most valuable things in particle physics is a place to do experiments," Garbincius said. "These are `physics spigots.' Data flows from them. It became apparent with the reduction of the conventional fixed-target program, and with only two locations for the collider program at CDF and DZero, that there would simply be fewer places to do experiments."

The enclosure was designed in a manner that would accommodate the detector for the proposed BTeV experiment at the Tevatron, investigating the properties of the bottom quarks for CP violation and rare decays. The bottom quark is the second heaviest after the top quark, and many physicists feel that these heavy hadrons are the most promising for discoveries in new physics.

Construction of the new area began in January 1998, and the existing CZero spectrometer room was demolished along with the Tevatron tunnel segment. In its place are the below-ground experimental hall, an above-ground assembly building and an equipment access.

The new experimental area is about the size of a tennis court at 80 feet long by 30 feet wide, with a 22-foot ceiling. The Tevatron tunnel was also demolished and reconfigured for a distance of 120 feet upstream and downstream from the planned interaction point, allowing for future experimental apparatus and for an equipment bypass tunnel around the experimental hall.

A high-bay staging hall is equipped with a loading dock and a 30-ton capacity bridge crane. The shielding door is a major feat on its own: 400 tons of concrete, measuring 20 feet high by 20 feet wide by 13 feet thick, moved by rollers and jacks, and modeled on the system used at CDF. Opening or closing the door, to move equipment in or out, or to prepare for beam, will take about half a day.

"It's not something we'll want to do very often," Garbincius remarked dryly.

At the time Fermilab was seeking funds for CZero, projects of that size had to appear as Line Items in the President's budget, with review by both Congress and the Office of Management and Budget.

"It had to appear the same way as the Main Injector project," Garbincius said, adding that those budgetary constraints were no longer the case for a project this size.

Plenty of work remains before physics data can flow from this new spigot. Final steps include: completing utility connections up to the assembly building, adding power and water, and adding the "counting room" facilities where data is collected.

"We did as much as we could underground, and we deferred finishing off the utilities and the building," Garbincius explained. "When an experiment is approved, we'll have to find the money to complete these later phases."

Besides the approval and preparation of a new experiment, CZero will also need a major effort to design and implement a plan for proton-antiproton collisions at the location.

Like all projects, this one required a large cast of key people to make it happen. Garbincius said the list included many from the Facilities Engineering Services Section and from the Beams Division: project engineer Tom Lackowski, design coordinator Paul Lahn, construction coordinators Jeff Moecher, Ron Foutch and Tony Ramos; retiree John Grimson returned part-time to work with Jeff Sims on the shielding door; Bill Wickenberg coordinated the groups removing and replacing the accelerator; Alex Martinez and the Beams Division Cryogenics Support Department installed the cryogenics; Tom Moreland designed and managed the electrical power bus and water piping; Rob Reilly designed component supports and oversaw installation; Dave Augustine and the BD/Mechanical Support Department performed the tunnel installation.

"I'm sure there are people I forgot to acknowledge," Garbincius said, "but these are the people who were with the project for a long time and really made it work. I'm especially pleased that we were ale to accomplish this heavy construction without a single lost-time injury."